One side of my forehead is bigger than the other. How can I fix my forehead? (Photo)

You have very large and prominent brow bones of which one side of that brow bone (and the forehead above it) is more developed than the other. (enlargement of the frontal sinus cavity) If the only goal is to get one side of the enlarged brow bone/forehead reduced enough to match the other side then burring reduction may be sufficient. But a preoperative 3D CT scan of your forehead is needed to make a more accurate assessment of the forehead bony anatomy.

If you are over 25 and have an asymmetrical hairline, a hair transplant is the best way to balance it as it is easy to do this with transplants. Do you have other areas where the hair is thinning such as the crown of your head